Here's a new phenomenon: carrying out Underground track repairs whilst a
train
is in service, which is deliberately held up for that purpose!

as others have said it is nothing new. Surely you would prefer that a
running repair was made in this effective fashion rather than being
turfed off the train, the line suspended and you being delayed?

I was not complaining - merely pointing out something I had not seen before.

I was once on a North London Line train when the (heritage unit) diesel failed,
and the driver got out and effected mechanical repairs whilst we all watched in
admiration!

But I do have a genuine concern for safety - as Counsel who prosecutes for the
Health and Safety Executive on occasion. Working in a dark tunnel, with two
electrified rails fills me with horror!

Marc.